Method of transporting viscous hydrocarbons

ABSTRACT

An improvement in the method of transporting viscous hydrocarbons through pipes is disclosed. Briefly, the improvement comprises adding water, certain specific surfactants and a basic material to the hydrocarbon. The resulting emulsion has a much lower viscosity and is more easily transported.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of application Ser.No. 918,015, filed June 22, 1978 now abandoned.

Application Ser. No. 13,358, filed Feb. 21, 1979, and having the sameassignee as the present application, discloses and claims an improvementin the method of transporting viscous hydrocarbons through pipes whereinthe improvement comprises adding water containing an effective amount ofa low molecular weight alkaryl sulfonate.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is in the general field of improved methods of pumpingviscous hydrocarbons through a pipe, such as a well-bore or a pipeline.

2. General Background

The movement of heavy crudes through pipes is difficult because of theirhigh viscosity and resulting low mobility. One method of improving themovement of these heavy crudes has included adding to the crude lighterhydrocarbons (e.g. kerosine distillate). This reduces the viscosity andthereby improves the mobility. This method has the disadvantage that isis expensive and the kerosine distillate is becoming difficult toobtain.

Another method of improving the movement of these heavy crudes is byheating them. This requires the installation of expensive heatingequipment and thus is an expensive process.

The use of oil-in-water emulsions, which use surfactants to form theemulsion is known in the art.

I have found that the use of a small amount of a basic compound (e.g.NaOH) in conjunction with certain specific surfactants provides animprovement. The use of the basic compound reduces the amount ofsurfactant required and thereby reduces the cost. Furthermore, the useof the basic compound enables the use of such a small amount ofsurfactant that refining problems are reduced or eliminated.

BRIEF SUMMARY OF THE INVENTION

Briefly stated, the present invention is directed to an improvement inthe method of pumping a viscous hydrocarbon through a pipe wherein theimprovement comprises forming an oil-in-water emulsion by adding to saidhydrocarbon from about 20 to about 80 volume percent water, containingminor but effective amounts of the combination of (a) an alkali metal orammonium hydroxide and (b) certain specific surfactants which areselected from the group consisting of water-soluble alkylbenzenesulfonates and an ethoxylated phenol nonionic.

DETAILED DESCRIPTION

Insofar as is known my method is suitable for use with any viscous crudeoil.

The amount of water which is used is suitably in the range of about 20to about 80 volume percent based on the hydrocarbon. A preferred amountof water is in the range of about 40 to 60 volume percent. The water canbe pure or can have a relatively high amount of dissolved solids. Anywater normally found in the proximity of a producing oil-well issuitable.

Suitable basic compounds for addition to the water include thehydroxides of sodium, potassium and ammonium. Sodium hydroxide ispreferred by reason of cost and availability. The amount of basiccompound present in the water suitably is in the range of about 400 toabout 10,000 parts per million (ppm) by weight. Preferably, the amountof basic compound is in the range of about 600 to about 1250 parts permillion by weight.

Two types of surfactants are suitable for use in my invention. The firsttype is a sodium or potassium salt of an alkylbenzene sulfonatecontaining about 8 to about 14 carbon atoms in the alkyl group orgroups. The benzene can be either monoalkyl- or dialkyl-substituted, butpreferably is monoalkyl. The alkyl group or groups can be linear orbranched chain. The preferred surfactant, in this type, is a sodiummonoalkylbenzene sulfonate wherein the alkyl group contains about 11 toabout 13 carbon atoms.

The second type of surfactant comprises two specific nonionics. First,an ethoxylated mono- or dialkyl phenol, wherein each alkyl groupcontains from about 8 to about 12 carbon atoms, said ethoxylated alkylphenol containing from about 20 to about 100 ethoxy groups, preferablyfrom about 30 to about 70 ethoxy groups. Second, in some cases theethoxylated phenol can be in combination with a polyethylene glycol,said polyethylene glycol having a molecular weight in the range of about1,000 to about 3,000, preferably about 1800 to about 2200. When theglycol is present typically the combination contains a phenol to glycolweight ratio of about 4:1.

A suitable amount of surfactant is in the range of about 10 to about 500parts by million by weight, preferably about 50 to about 100 parts permillion (ppm) by weight.

In order to illustrate the nature of the present invention still moreclearly the following examples will be given. It is to be understood,however, that the invention is not to be limited to the specificconditions or details set forth in these examples except insofar as suchlimitations are specified in the appended claims.

The following materials were used in the tests described herein:

Crude Oil--Goodwin lease crude from Cat Canyon oil field, Santa Maria,California

Water--Goodwin synthetic (Water prepared in laboratory to simulate waterproduced at the well. It contained 4720 ppm total solids.)

Sodium Hydroxide--C.P. grade, pellet form

Surfactants

A--sodium monoalkylbenzene sulfonate having a molecular weight ofapproximately 334

B--A nonionic as described in the foregoing.

The nonionic will be identified more specifically in the examples.

Viscosities were determined using a Brookfield viscometer, Model LV withNo. 3 spindle. The procedure is described below.

Test Procedure

Three hundred ml of crude oil, preheated in a large container to about93° C. in a laboratory oven, was transferred to a Waring blender andstirred at medium speed until homogeneous. Stirring was stopped,temperature recorded, and the viscosity measured using the Brookfieldviscometer at RPM's (revolutions per minute) of 6, 12, 30 and 60.Viscosity was calculated by using a multiplication factor of 200, 100,40 and 20 for the respective speeds times the dial reading on theviscometer.

It may be well to mention that the final result at 6 RPM is anindication of the stability of the solution being tested.

EXAMPLE 1

This example shows the viscosity values obtained on the crude alone andthe crude containing 50 volume percent water which contains 5,000 ppmSurfactant "A".

The results are shown in Table 1.

                  TABLE 1                                                         ______________________________________                                                         CRUDE 50 VOL                                                                  % IN WATER CONTAIN-                                          CRUDE ALONE      ING 5,000 PPM SURF. "A"                                             Dial     Viscosity                                                                              Dial      Viscosity                                  RPM    Reading  cp       Reading   cp                                         ______________________________________                                         6     21       4,200    0.5       100                                        12     40       4,000    2.0       200                                        30     94       3,766    3.0       120                                        60     Offscale --       3.6        72                                        30     87       3,480    3.0       120                                        12     34       3,400    2.0       200                                         6     15.8     3,160    1.5       300                                        Test Temperature 82° C.                                                                 Test Temperature 49° C.                               ______________________________________                                    

EXAMPLE 2

Example 1 was repeated except that the amount of Surfactant "A" was 1250ppm.

The results are shown in Table 2.

                  TABLE 2                                                         ______________________________________                                                         CRUDE 50 VOL                                                                  % IN WATER CONTAIN- -CRUDE ALONE ING 1,250 PPM SURF.                          "A"                                                                 Dial     Viscosity                                                                              Dial      Viscosity                                  RPM    Reading  CP       Reading   CP                                         ______________________________________                                         6     15.5     3,100    4         800                                        12     29       2,900    5.5       550                                        30     62       2,480    8         320                                        60     69       1,380    11.8      236                                        30     61       2,440    7         280                                        12     25       2,500    4         400                                         6     11.5     2,300    3.2       640                                        Test Temperature 96° C.                                                                 Test Temperature 77° C.                               ______________________________________                                    

EXAMPLE 3

This example shows the results obtained using 1250 ppm NaOH in water.

The results are shown in Table 3.

                  TABLE 3                                                         ______________________________________                                                         CRUDE 50 VOL                                                                  % IN WATER CON-                                              CRUDE ALONE      TAINING 1,250 PPM NaOH                                              Dial     Viscosity                                                                              Dial      Viscosity                                  RPM    Reading  CP       Reading   CP                                         ______________________________________                                         6     20       4,000    1         200                                        12     36       3,600    1.5       150                                        30     84       3,360    1.5        60                                        60     Off scale                                                                              --       4.3        86                                        30     81       3,240    2.5       100                                        12     33       3,300    2         200                                        6      17       3,400    1         200                                        Test Temperature 82° C.                                                                 Test Temperature 67° C.                               ______________________________________                                    

EXAMPLE 4

This example illustrates the improvement obtained using my invention.

Example 2 was repeated except that the amount of Surfactant "A" was 50ppm and the aqueous solution contained 625 ppm NaOH.

The results are shown in Table 4.

                  TABLE 4                                                         ______________________________________                                                         CRUDE 50 VOL                                                                  % IN WATER CONTAIN-                                                           ING 50 PPM SURF. - "A" AND 625 PPM                           CRUDE ALONE       SODIUM HYDROXIDE                                                   Dial     Viscosity                                                                              Dial      Viscosity                                  RPM    Reading  CP       Reading   CP                                         ______________________________________                                         6     21       4,200    0.25      50                                         12     39       3,900    1         100                                        30     94       3,760    2         80                                         60     Off scale                                                                              --       2         40                                         30     90       3,600    1         40                                         12     35       3,500    1         100                                         6     17       3,400    .25       50                                         Test Temperature 71° C.                                                                 Test Temperature 66° C.                               ______________________________________                                    

EXAMPLE 5

This example used a different sample of Cat Canyon crude. The exampleillustrates the results obtained using equal amounts of surfactant andNaOH.

The procedure was the same as in Example 2. Viscosity values wereobtained on crude oil alone and on crude oil plus an equal amount ofwater (300 ml each), wherein the water contained 500 ppm Surfactant "A".

The results are shown in Table 5.

                  TABLE 5                                                         ______________________________________                                                         CRUDE OIL PLUS 300 ML                                                         WATER CONTAINING 500                                         CRUDE OIL        PPM SURF. "A" AND 500                                        ALONE (300 ML)   PPM SODIUM HYDROXIDE                                                Dial     Viscosity                                                                              Dial      Viscosity                                  RPM    Reading  CP       Reading   CP                                         ______________________________________                                         6     48       9,600    1.5       300                                        12       91.5   9,150    2.5       250                                        30     Off scale                                                                              --       4         160                                        60     Off scale                                                                              --       6.5       130                                        30     Off scale                                                                              --       4         160                                        12     91       9,100    2.3       230                                         6     46       9,200    1.5       300                                        Test Temperature 82° C.                                                                 Test Temperature 68° C.                               ______________________________________                                    

EXAMPLE 6

This example illustrates the results obtained using 625 ppm NaOH inwater.

The results are shown in Table 6.

                  TABLE 6                                                         ______________________________________                                                         CRUDE 50 VOL                                                                  % IN WATER                                                   CRUDE ALONE      CONTAINING 625 PPM NaOH                                             Dial     Viscosity                                                                              Dial      Viscosity                                  RPM    Reading  cp       Reading   cp                                         ______________________________________                                         6     26       5,200    1         200                                        12     50       5,000    1.5       150                                        30     Offscale --       3         120                                        60     Offscale --       7         140                                        30     Offscale --       8.5       340                                        12     52       5,200    7         700                                         6     26       5,200    6         1200                                       Test Temperature 82° C.                                                                 Test Temperature 71° C.                               ______________________________________                                    

EXAMPLE 7

This example illustrates the results obtained using a 125 ppm of anonionic in water. The nonionic was a combination of an ethoxylatedalkyl phenol, containing 50 moles of ethylene oxide per mole of alkylphenol, and a polyethylene glycol wherein the ethoxylated phenol topolyethylene glycol weight ratio was 4:1. The polyethylene glycol had amolecular weight in the range of about 1,000 to about 3,000.

The results are shown in Table 7.

                  TABLE 7                                                         ______________________________________                                                         CRUDE 50 VOL % IN                                                             WATER containing 125                                         CRUDE ALONE       PPM NONIONIC SURF.                                                 Dial     Viscosity                                                                              Dial      Viscosity                                  RPM    Reading  CP       Reading   CP                                         ______________________________________                                         6     19       3,800    52.3      10,460                                     12     35.7     3,570    93        9,300                                      30     84.3     3,372    Off scale --                                         60     Off scale                                                                              --       Off scale --                                         30     81       3,240    Off scale --                                         12     32       3,200    95        9,500                                       6     16       3,200    48        9,600                                      Test Temperature 82° C.                                                                 Test Temperature 79° C.                               ______________________________________                                    

EXAMPLE 8

This example illustrates the results obtained using a combination of 625ppm NaOH and 100 ppm of the nonionic surfactant used in Example 7.

The results are shown in Table 8.

                  TABLE 8                                                         ______________________________________                                                         CRUDE 50 VOL                                                                  % IN WATER CON-                                                               TAINING 625 PPM NaOH                                         CRUDE ALONE      AND 100 PPM NONIONIC                                                Dial     Viscosity                                                                              Dial      Viscosity                                  RPM    Reading  CP       Reading   CP                                         ______________________________________                                          6    30       6,000    1         200                                        12     55       5,500    1         100                                        30     Off scale                                                                              --       1          40                                        60     Off scale                                                                              --       2          40                                        30     Off scale                                                                              --       3         120                                        12     57       5,700    3         300                                         6     31       6,200    3         600                                        Test Temperature 82° C.                                                                 Test Temperature 71° C.                               ______________________________________                                    

EXAMPLE 9

This example illustrates the results obtained using a combination of1250 ppm NaOH and 50 ppm of the nonionic surfactant used in Example 8.

The results are shown in Table 9.

                  TABLE 9                                                         ______________________________________                                                         CRUDE 50 VOL                                                                  % IN WATER CON-                                                               TAINING 1250 PPM NaOH                                        CRUDE ALONE      AND 50 PPM NONIONIC                                                 Dial     Viscosity                                                                              Dial      Viscosity                                  RPM    Reading  CP       Reading   CP                                         ______________________________________                                         6     23       4,600    0.5       100                                        12     41.5     4,150    1         100                                        30     99       3,960    1.5       60                                         60     Off scale                                                                              --       3         60                                         30     98       3,920    1.5       60                                         12     39       3,900    1         100                                         6     18.5     3,700    0.5       100                                        Test Temperature 88° C.                                                                 Test Temperature 66° C.                               ______________________________________                                    

EXAMPLE 10

This example illustrates the results obtained using a combination of 700ppm NaOH and 100 ppm of a different nonionic surfactant than used inExamples 7-9. The nonionic was an ethoxylated octyl phenol containing 70moles of ethylene oxide per mole of octyl phenol.

The results are shown in Table 10.

                  TABLE 10                                                        ______________________________________                                                         CRUDE 50 VOL                                                                  % IN WATER CON-                                                               TAINING 700 PPM NaOH                                         CRUDE ALONE      AND 100 PPM NONIONIC                                                Dial     Viscosity                                                                              Dial      Viscosity                                  RPM    Reading  CP       Reading   CP                                         ______________________________________                                         6     15.5     3,100    1.5       300                                        12     31       3,100    2.5       250                                        30     77       3,080    3.5       140                                        60     Off scale                                                                              --       7         140                                        30     77       3,080    3         120                                        12     31       3,100    1.5       150                                         6     11.5     2,300    1.5       300                                        Test Temperature 93° C.                                                                 Test Temperature 74° C.                               ______________________________________                                    

Thus, having described the invention in detail, it will be understood bythose skilled in the art that certain variations and modifications maybe made without departing from the spirit and scope of the invention asdefined herein and in the appended claims.

I claim:
 1. In the method of pumping a viscous hydrocarbon through apipe the improvement which comprises forming an oil-in-water emulsion byadding to said hydrocarbon from about 20 to about 80 volume percent ofan aqueous solution, based on said hydrocarbon, containing about 400 to10,000 parts per million alkali metal or ammonium hydroxide and about 10to about 500 parts per million of a surfactant selected from the groupconsisting of:(a) water-soluble alkylbenzene sulfonates wherein thealkyl group or groups contain about 8 to about 14 carbon atoms, and (b)the combination of an ethoxylated mono- or dialkyl phenol, wherein thealkyl groups contain from about 8 to about 12 carbon atoms and saidphenol contains from about 20 to about 100 ethoxy groups and apolyethylene glycol said combination having a phenol to glycol weightratio of about 4:1, said polyethylene glycol having a molecular weightin the range of about 1,000 to about 3,000.
 2. The improved method ofclaim 1 wherein the surfactant is a water-soluble alkylbenzene sulfonatewherein the alkyl groups contain about 8 to about 14 carbon atoms. 3.The improved method of claim 2 wherein the surfactant is a sodiummonoalkylbenzene sulfonate wherein the alkyl group contains about 11 toabout 13 carbon atoms.
 4. The improved method of claim 1 wherein thesurfactant is a combination of an ethoxylated mono- or dialkyl phenol,wherein the alkyl group contains from about 8 to about 12 carbon atoms,and wherein from about 20 to about 100 ethoxy groups are present, and apolyethylene glycol, said combination having a phenol to glycol weightratio of about 4:1.
 5. The improved method of claim 1 wherein (a) theamount of aqueous solution added to said hydrocarbon is from about 40 toabout 60 weight percent and (b) the alkali metal or ammonium hydroxideis sodium hydroxide.
 6. The improved method of claim 5 wherein thesurfactant is a water-soluble alkylbenzene sulfonate wherein the alkylgroups contain about 8 to about 14 carbon atoms.
 7. The improved methodof claim 6 wherein the surfactant is a sodium monoalkylbenzene sulfonatewherein the alkyl group contains about 11 to about 13 carbon atoms. 8.The improved method of claim 5 wherein the surfactant is a combinationof an ethoxylated mono- or dialkyl phenol, wherein the alkyl groupcontains from about 8 to about 12 carbon atoms, and wherein from about20 to about 100 ethoxy groups are present, and a polyethylene glycol,said combination having a phenol to glycol weight ratio of about 4:1. 9.The improved method of claim 7 wherein the amount of sodium hydroxide isabout 600 to about 1250 parts per million and the amount of surfactantis about 50 to about 100 parts per million.
 10. The improved method ofclaim 8 wherein the amount of sodium hydroxide is about 600 to about1250 parts per million and the amount of surfactant is about 50 to about100 parts per million.